This circuit, found in a 1964 US documentation, consists of a selective amplifier that lets only 10 Hz pass around a 400 Hz center frequency with the indicated components.
This circuit that uses a mechanical tuning fork was found in Radio Electronics magazine from June...
In the presence of the supply voltage of a 3 to 12 V circuit, this circuit causes the LED to...
This circuit supplies a voltage of 110 V from car battery with 110 V x 100 W output. Transformer...